The present invention concerns a cleaning arrangement of a sieve or screen provided with openings through which air flows, with a brush arranged on the air inlet side of and having bristles penetrating openings of the sieve.
EP 489975 A discloses a sieve arrangement having a perforated filter element and a cleaning brush arranged on the air outlet side of the sieve. Contaminants accumulating in the perforated sieve are punched out of the perforations by the bristles of the brush and are blown away and removed by a blower arrangement located under the sieve. The brush punches out the contaminants against the air flow passing through the sieve, so that the resulting disadvantage is that the contaminants are not efficiently sucked away by the blower but, due to the air flow, are often pushed again into the sieve by the air flow.
A similar sieve arrangement is disclosed in EP 0 985 439 A and includes a rotating sieve, with rotating brushes being mounted at its outlet side and having bristles that penetrate its air inlet openings. The brushes are located in the operating region of a suction device arranged on the air inlet side of the sieve. Here, too, the suction device must operate against the direction of the air flow, so that relatively high suction power is required.
Another cleaning device for a sieve is disclosed in DE 453 597 A and includes roll-shaped brushes arranged on the inlet side of the sieve. Opposite the brushes on the outlet side, an unbroken plate with sector-shaped cutouts is arranged. This should result in the contaminants, that are pushed out of the sieve by the brushes, falling downward as a result of the air flow interruption caused by the plate. Here it is considered a disadvantage that the contaminants that fall downward can reach the air flow below the plate, so that the filtration effect achieved is inadequate.
According to the present invention, there is provided an improved cleaning arrangement for a sieve.
An object of the invention is to provide an improved sieve cleaning arrangement including a brush arrangement at the inlet side of the sieve, as determined relative to a stream of air flowing through openings, which operates to poke contaminants through the sieve, and to provide a suction device on the outlet side of the sieve for removing the contaminants that have been poked through.
A more specific object of the invention is to provide a sieve together with a brush arrangement and a suction device, as set forth in the previous object, wherein the sieve is flat and circular and is mounted for rotation about a first axis while the suction device is fixed.
Yet another specific object is to provide a cooling device as set forth in the immediately preceding object which includes a second suction device mounted at the inlet side of the sieve for removing contaminants loosened by the brush arrangement.
These and other objects of the invention will become apparent from a reading of the ensuing description together with the appended drawings.